Aström J A
CSC-IT Center for Science, Esbo, Finland.
Phys Rev E Stat Nonlin Soft Matter Phys. 2009 Oct;80(4 Pt 2):046113. doi: 10.1103/PhysRevE.80.046113. Epub 2009 Oct 19.
Recently there has been some suggestions that fragmentation of thin brittle sheets is qualitatively different from pure two-dimensional fragmentation. The obvious reason for such a discrepancy is the possibility of the sheet to deform out of plane. There is a generic crack-branching mechanism that creates power-law fragment size distribution in the small fragment range for two-dimensional (2D) and three-dimensional bulk fragmentation with the power exponent (2D-1)/D. For thin sheets, the power exponent seems to be close to 1.2 which differs from the D=2 exponent 1.5. In order to make a distinct separation between sheet and 2D fragmentation, high-resolution fragment size distributions are required for fragmentation models with minimal differencies other than dimensionality. Here a very efficient numerical model which can be switched from 2D fragmentation to out-of-plane sheet fragmentation with minimal changes is used to produce high-resolution fragment size distribution for the two cases. The model results cast some doubt on the existence of separate universality classes for sheet and 2D fragmentation.
最近有一些观点认为，薄脆片的破碎在性质上与纯二维破碎不同。出现这种差异的明显原因是薄片可能发生面外变形。存在一种通用的裂纹分支机制，它在小碎片范围内为二维（2D）和三维体破碎产生幂律碎片尺寸分布，幂指数为(2D - 1)/D。对于薄片，幂指数似乎接近1.2，这与D = 2时的指数1.5不同。为了明确区分薄片破碎和二维破碎，对于除维度外差异最小的破碎模型，需要高分辨率的碎片尺寸分布。这里使用一个非常有效的数值模型，该模型可以通过最小的改变从二维破碎切换到面外薄片破碎，以生成这两种情况的高分辨率碎片尺寸分布。模型结果对薄片破碎和二维破碎存在单独的普适类这一观点提出了一些质疑。
